Matthew M. Knight
A5061161174- Astro and Planetary Science
- Stellar, planetary, and galactic studies
- Planetary Science and Exploration
- Isotope Analysis in Ecology
- Atmospheric Ozone and Climate
- Gamma-ray bursts and supernovae
- Solar and Space Plasma Dynamics
- Nuclear Physics and Applications
- Astrophysics and Star Formation Studies
- Space Exploration and Technology
- Astronomy and Astrophysical Research
- Astronomical Observations and Instrumentation
- Spacecraft and Cryogenic Technologies
- Astronomical and nuclear sciences
- Nuclear physics research studies
- Space Satellite Systems and Control
- History and Developments in Astronomy
- Atomic and Subatomic Physics Research
- High-pressure geophysics and materials
- Atomic and Molecular Physics
- SAS software applications and methods
- Topic Modeling
- Geomagnetism and Paleomagnetism Studies
- Adaptive optics and wavefront sensing
- Geological and Geochemical Analysis
United States Naval Academy
2020-2025
Lockheed Martin (Australia)
2024
University of Maryland, College Park
2007-2023
Liverpool John Moores University
2023
Campbell Collaboration
2022
Lockheed Martin (Canada)
2022
Lowell Observatory
2010-2017
Johns Hopkins University Applied Physics Laboratory
2012-2015
Association of Universities For Research In Astronomy
2007
U.S. National Science Foundation
2007
We introduce Codex, a GPT language model fine-tuned on publicly available code from GitHub, and study its Python code-writing capabilities. A distinct production version of Codex powers GitHub Copilot. On HumanEval, new evaluation set we release to measure functional correctness for synthesizing programs docstrings, our solves 28.8% the problems, while GPT-3 0% GPT-J 11.4%. Furthermore, find that repeated sampling is surprisingly effective strategy producing working solutions difficult...
We fine-tune GPT-3 to answer long-form questions using a text-based web-browsing environment, which allows the model search and navigate web. By setting up task so that it can be performed by humans, we are able train models on imitation learning, then optimize quality with human feedback. To make evaluation of factual accuracy easier, must collect references while browsing in support their answers. evaluate our ELI5, dataset asked Reddit users. Our best is obtained fine-tuning behavior...
Abstract The Double Asteroid Redirection Test (DART) spacecraft successfully performed the first test of a kinetic impactor for asteroid deflection by impacting Dimorphos, secondary near-Earth binary (65803) Didymos, and changing orbital period Dimorphos. A change in approximately 7 min was expected if incident momentum from DART directly transferred to target perfectly inelastic collision 1 , but studies probable impact conditions properties indicated that considerable enhancement ( β )...
Some active asteroids have been proposed to be formed as a result of impact events1. Because are generally discovered by chance only after their tails fully formed, the process how ejecta evolve into tail has, our knowledge, not directly observed. The Double Asteroid Redirection Test (DART) mission NASA2, in addition having successfully changed orbital period Dimorphos3, demonstrated activation an asteroid resulting from under precisely known conditions. Here we report observations DART with...
Abstract NASA's Double Asteroid Redirection Test (DART) mission was the first to demonstrate asteroid deflection, and mission's Level 1 requirements guided its planetary defense investigations. Here, we summarize DART's achievement of those requirements. On 2022 September 26, DART spacecraft impacted Dimorphos, secondary member Didymos near-Earth binary system, demonstrating an autonomously navigated kinetic impact into with limited prior knowledge for defense. Months subsequent Earth-based...
On 4 July 2005, many observatories around the world and in space observed collision of Deep Impact with comet 9P/Tempel 1 or its aftermath. This was an unprecedented coordinated observational campaign. These data show that (i) there new material after impact compositionally different from seen before impact; (ii) ratio dust mass to gas ejecta much larger than (iii) activity did not last more a few days, by 9 comet's behavior indistinguishable pre-impact behavior; (iv) were interesting...
The Vera C. Rubin Observatory is expected to start the Legacy Survey of Space and Time (LSST) in early mid-2025. This multi-band wide-field synoptic survey will transform our view solar system, with discovery monitoring over 5 million small bodies.The final strategy chosen for LSST has direct implications on discoverability characterization system minor planets passing interstellar objects. Creating an inventory one four main science drivers. observing cadence a complex optimization problem...
Earth- and space-based observations provide synergistic information for space mission encounters by providing data over longer timescales, at different wavelengths using techniques that are impossible with an in situ flyby. We report here such support of the EPOXI spacecraft flyby comet 103P/Hartley 2. The nucleus is small dark, exhibited a very rapidly changing rotation period. Prior to onset activity, period was ∼16.4 hr. Starting 2010 August changed from 16.6 hr near 19 December. With...
We present analysis of the photometry more than 900 Kreutz comets observed by SOHO from 1996 to 2005. The have "sungrazing" orbits with q≈ 1–2 R☉, high inclinations (i ≈ 143°), and periods 500–1000 years. find that they do not a bimodal distance peak brightness as previously reported, but instead 10.5 R☉ 14 (prior perihelion), suggesting there is continuum compositions rather two distinct subpopulations. light curves rates brightening, typically ∝ r−7.3 ± 2.0 when first (at distances 30–35...
This review addresses our current understanding of comets that venture close to the Sun, and are hence exposed much more extreme conditions than typically studied from Earth. The solar heating plasma environments these objects encounter change many aspects their behaviour, thus yielding valuable information on both themselves complements other data we have primitive system bodies, as well near-solar environment which they traverse. We propose clear definitions for comets: use term near-Sun...
On 2016 Feb 19, nine Rosetta instruments serendipitously observed an outburst of gas and dust from the nucleus comet 67P/Churyumov-Gerasimenko. Among these were cameras spectrometers ranging UV over visible to microwave wavelengths, in situ gas, plasma instruments, one collector. At 09:40 a cloud developed at edge image shadowed region nucleus. Over next two hours recorded signature that significantly exceeded background. The enhancement ranged 50 per cent neutral density factors >100...
Abstract We observed the newly discovered hyperbolic minor planet 1I/‘Oumuamua (2017 U1) on 2017 October 30 with Lowell Observatory’s 4.3 m Discovery Channel Telescope. From these observations, we derived a partial lightcurve peak-to-trough amplitude of at least 1.2 mag. This segment rules out rotation periods less than 3 hr and suggests that period is 5 hr. On assumption variability due to changing cross-section, axial ratio 3:1. saw no evidence for coma or tail in either individual images...
Abstract We performed photometric observations of the binary near-Earth asteroid (65803) Didymos in support Double Asteroid Redirection Test (DART) mission that will test Kinetic Impactor technology for diverting dangerous asteroids. It hit secondary, called Dimorphos, on 2022 September 26. observed with 11 telescopes diameters from 3.5 to 10.4 m during four apparitions 2015–2021, obtaining data rms residuals 0.006 0.030 mag. analyzed light-curve and decomposed them into primary rotational...
Context. On September 26, 2022, the NASA DART mission impacted asteroid Dimorphos, smaller component of Didymos binary system. This provided a unique opportunity to observe, in real time, evolution ejecta cloud produced by impact and formation tail. Aims. We present observations performed with MUSE instrument at Very Large Telescope characterise morphology, spectral properties, ejecta. The system was observed on 11 nights from just before almost one month post-impact, using both wide-field...
Abstract On 2022 September 26, the Double Asteroid Redirection Test (DART) spacecraft impacted Dimorphos, satellite of binary near-Earth asteroid (65803) Didymos. This demonstrated efficacy a kinetic impactor for planetary defense by changing orbital period Dimorphos 33 minutes. Measuring change relied heavily on coordinated campaign lightcurve photometry designed to detect mutual events (occultations and eclipses) as direct probe satellite’s period. A total 28 telescopes contributed 224...
Abstract Sunskirting asteroid (3200) Phaethon has been repeatedly observed in Solar Terrestrial Relations Observatory (STEREO) Heliospheric Imager 1 (HI1) imagery to anomalously brighten and produce an antisunward tail for a few days near each perihelion passage, phenomena previously attributed the ejection of micron-sized dust grains. Color imaging by (SOHO) Large Angle Spectrometric Coronagraph (LASCO) during 2022 May apparition indicates that brightening development instead capture...
We review the evidence for buried ice in asteroid belt; specifically questions around so-called Main Belt Comets (MBCs). summarise water throughout Solar System, and describe various methods detecting it, including remote sensing from ultraviolet to radio wavelengths. progress first decade of study MBCs, observations, modelling survival, discussion on their origins. then look at which will likely be most effective further progress, key challenge direct detection (escaping) these bodies.
Abstract We report observations of nine main-belt comets (MBCs) or candidate MBCs, most which were obtained when the targets apparently inactive. find effective nucleus radii (assuming albedos p V = 0.05 ± 0.02) r n (0.24 0.05) km for 238P/Read, (0.9 0.2) 313P/Gibbs, (0.6 0.1) 324P/La Sagra, (1.0 426P/PANSTARRS, (0.5 427P/ATLAS, < (0.3 P/2016 J1-A (PANSTARRS), (0.17 0.04) J1-B ≤ P/2017 S9 recently redesignated 455P/PANSTARRS, and (0.4 P/2019 A3 (PANSTARRS). identify evidence activity in...
Abstract The impact of the Double Asteroid Redirection Test spacecraft into Dimorphos, moon asteroid Didymos, changed Dimorphos’s orbit substantially, largely from ejection material. We present results 12 Earth-based facilities involved in a world-wide campaign to monitor brightness and morphology ejecta first 35 days after impact. After an initial brightening ∼1.4 mag, we find consistent dimming rates 0.11–0.12 mag day −1 week, 0.08–0.09 over entire study period. system returned its...
Abstract We report the detection of water vapor associated with main-belt comet 358P/PANSTARRS on UT 2024 January 8–9 using NIRSPEC instrument board JWST. derive a production rate <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>Q</mml:mi> </mml:mrow> <mml:mi mathvariant="normal">H</mml:mi> <mml:mn>2</mml:mn> </mml:msub> mathvariant="normal">O</mml:mi> <mml:mo>=</mml:mo> <mml:mo stretchy="false">(</mml:mo> <mml:mn>5.0</mml:mn>...